Chen, Suming
Xiong, Caiqiao
Liu, Huihui
Wan, Qiongqiong
Hou, Jian
He, Qing
Badu-Tawiah, Abraham
Nie, Zongxiu
Article History
Received: 1 July 2014
Accepted: 3 November 2014
First Online: 5 February 2015
Competing interests
: The authors declare no competing financial interests.